Democracy is a terrible form of government unless in a very small State. But, even then people need to be educated, and have the ability to think logically and constructively, and understand key sciences which prepares them for the task of helping to maintain the societies order. The only system that would really work against corruption is for a society to have a written agreement with itself that declares what the absolute laws are and that under no cases can they be violated. Sort of like Plato's philosopher kings of his republic but rather than men -- you have law itself. But not law which grew from a man's mind, but that natural Law which we all know and can agree on.
There was an old book written called Rex Lex; which is latin for "the King is Law" and one written in response to it called Lex Rex - The Law is King.
While we have flawed humans deciding laws on the fly through "elected" bodies there will always be corruption. The only way to stop this is to take the power to make up laws away from humans and merely enforce the laws we all have written on our hearts, do not murder, do not steal, do not lie, etc. Law isn't that complex and doesn't need all these parasites pretending like they order society for us and make things run smoothly. They are a burden and roadblock more than a legit governing body. But people don't understand these basic concepts and get sucked into politics and keep on supporting there own enslavement.
If a society in a state of civilization expects to remain ignorant and free - they expect what never was, and never will be. - Thomas Jefferson